Date Palm Genotypes Research Articles

Exploring the Influence of Date Palm Cultivars on Soil Microbiota

Plants thrive in diverse environments, where root-microbe interactions play a pivotal role. Date palm (Phoenix dactylifera L.), with its genetic diversity and resilience, is an ideal model for studying microbial adaptation to different genotypes and stresses. This study aimed to analyze the bacterial and fungal communities associated with traditional date palm cultivars and the widely cultivated “Deglet Nour” were explored using metabarcoding approaches. The microbial diversity analysis identified a rich community with 13,189 bacterial and 6442 fungal Amplicon Sequence Variants (ASVs). Actinobacteriota, Proteobacteria, and Bacteroidota dominated bacterial communities, while Ascomycota dominated fungal communities. Analysis of the microbial community revealed the emergence of two distinct clusters correlating with specific date palm cultivars, but fungal communities showed higher sensitivity to date palm genotype variations compared to bacterial communities. The commercial cultivar “Deglet Nour” exhibited a unique microbial composition enriched in pathogenic fungal taxa, which was correlated with its genetic distance. Overall, our study contributes to understanding the complex interactions between date palm genotypes and soil microbiota, highlighting the genotype role in microbial community structure, particularly among fungi. These findings suggest correlations between date palm genotype, stress tolerance, and microbial assembly, with implications for plant health and resilience. Further research is needed to elucidate genotype-specific microbial interactions and their role in enhancing plant resilience to environmental stresses.

Molecular Identification of Genetic Diversity and Population Structure in Moroccan Male Date Palm (Phoenix dactylifera L.) Using Inter-Simple Sequence Repeat, Direct Amplification of Minisatellite DNA, and Simple Sequence Repeat Markers

Understanding genetic diversity and population structure plays a vital role in the efficient use of available material in plant-breeding programs and in germplasm conservation strategies. In the present study, we aim to evaluate the genetic variations and population structure of male date palms from Morocco. The genetic diversity of 100 date palm (Phoenix dactylifera L.) genotypes was investigated using the performance of three types of molecular markers: inter-simple sequence repeats (ISSRs), direct amplification of minisatellite DNA (DAMD), and simple sequence repeats (SSRs). On the basis of their polymorphic information content (PIC) (ISSRs = 0.38; DAMD = 0.4; SSRs = 0.33), effective multiplex ratio (EMR) (ISSRs = 27.34; DAMD = 52.31; SSRs = 22.20), Resolving power Rp (ISSR = 13.81; DAMD = 28.73; SSR = 14.6), and marker index (MI) (ISSRs = 9.22; DAMD = 20.23; SSRs = 7.54) values, all markers used in our study are considered informative markers. Among them, DAMD markers demonstrated slightly higher informativeness compared to ISSR and SSR markers. A total of 216, 438, and 248 bands were, respectively, detected using ISSRs, DAMD, and SSRs, with 95%, 98% and 94% of polymorphism, respectively. The AMOVA results revealed considerable diversity within date palms. The PCOa results showed that males of Tinghir and Errachidia were regrouped into the same cluster, while males of Goulmima were separated into another group. A cluster and structure analysis separated the studied genotypes into three groups. One group comprises genotypes of males from Zagora with some female varieties scattered in this group. The second group includes male genotypes from Goulmima along with accessions of female and male varieties. The third group contains males of Errachidia, Tata and Tinghir populations. The cluster and structure analysis separated the studied genotypes according to their origin.

Phenotypic diversity of date-palm genotypes (Phoenix dactylifera L.) collected from Mundra of Kutch region

A wide range of variability with regard to fruit and pulp characters and taste was observed in date groves in Kutch region of Gujarat (India), which have been developed naturally from seeds. An exploration was undertaken to identify better genotypes of date palm (Phoenix dactylifera) based on their fruit quality and yield-attributing characteristics. A total of 14 fruit samples were collected and data were analysed for fruit characters. Among the different genotypes MDR2 was identified and marked superior with respect to fruiting characteristics like fruit weight (29.86 g), fruit length (53.12 mm) and quality characteristics (TSS 35.17 ºB). In India, the coastal strip of the Kutch region contains the only remaining natural date palm groves, which should be utilised and maintained to be used in future genetic improvement programmes.

Physico-chemical properties revealed huge diversity in 50 date palm (Phoenix dactylifera L.) genotypes

ABSTRACT Date palm has excellent economic value all over the world. Date palm genotypes grown in Pakistan are diverse in nature. The current study aimed to explore the diversity in 50 date palm genotypes collected from two different research stations in Punjab, Pakistan. The study findings are as follows: Dhakki had the highest fruit weight, pulp weight, fruit width and fruit volume. Jaman had a longer fruit length. Eedel Shah and Begum Jangi had greater fruit thickness and fruit perimeter, respectively. Makran showed a higher fruit area. Dedhi showed the highest stone weight, thickness and volume. Halmain had a longer stone length, and Sundari had an extended stone width. Makhi exhibited a higher stone perimeter and area. The Danda genotype had low weight and a small length of the stone. Begum Jangi and Peeli Sundar had small stone width. Seib and Shado had a higher moisture content in their fruits. The fruits of Baidhar and Khudraw-2 genotypes had the highest dry matter and reducing sugars. Champa Kali and Shakri had higher TSS levels in fruits. Halmain had higher juice pH. The fruits of Pathri and Makhi genotypes exhibited higher non-reducing sugars and carotenoids. In this study, a dendrogram was constructed to cluster 50 genotypes into five different clusters based on their physico-chemical characteristics. The correlation matrix and variable plot revealed positive and negative correlations between fruits traits and their biochemical properties conducive to the improvement of desired traits. Principal component analysis (PCA) revealed that Dhakki, Chohara, Baidhar, Karbalaen and Eedel Shah showed a higher genetic diversity; hence, in the scatter plot and biplot, these genotypes deviated from the centre of origin. Physico-chemical characteristics of data palm genotypes indicated a huge diversity among them, which could help select diverse parents, which is important for different breeding purposes.

Detecção da diversidade genética adaptativa e composição química em cultivares de tamareira e implicações no controle do bicudo vermelho da palmeira, Rhynchophorus ferrugineus Oliver

This study, about RPW and date palms, is under the scope of date palm bioecology and nutrition (nutritional ecology) which includes the integration of several areas of research such as date palm biochemistry, genetics, and RPW infestation behavior through various date palm cultivars. Date palm (Phoenix dactylifera L.; Arecaceae) production is under threat from the red palm weevil (RPW), Rhynchophorus ferrugineus Oliver. A better understanding of genetic diversity within date palm cultivars can be useful for its implementation within the insect IPM program in the future. Three indices, namely simple-sequence repeats (SSR) markers to elucidate genetic diversity, chemical components, and a natural infestation index of RPW, were used to evaluate the resistant or susceptible date palm cultivars in Qassim. Based on a field survey of RPW infestation within 79 date palm farms involving 11 cultivars at Qassim, the sensitivity and resistance cultivars were determined. The resistant date palm cultivars were Nabtat Ali, Shakrah, red Sukary, and um Kobar which had the lowest degree of RPW abundance %. Values of the essential minerals, nitrogen, phosphorus, potassium, and calcium within the date palm cultivars were also estimated. RPW abundance % was negatively correlated with the calcium content of date palm cultivars. The principal component analysis (PCA) revealed that the calcium content and RPW abundance % were highly affected by the cultivars. SSR markers of the date palm cluster tree divided genotypes into two main groups at similarity coefficients between 0.56 and 0.91. The 1st group included; Nabtet Ali, Red Sukary, Um Kobar, and Shakrah with similarity coefficients between 0.56, this group was the most resistant cultivars. Therefore, SSR markers were able to characterize and resolve genetic diversity in date palm cultivars for RPW resistance. When SSR markers coupled with higher calcium (Ca) content can efficiently replace indices in characterizing resistant date-palm genotypes with a high confidence level. Integration between date palm genetic diversity, chemical structures, and RPW infestations rates promoted the understanding of the interplay between the diversity of RPW management (short-time scale), and the resistance genes, plant nutrition, and dynamics of the diversity of RPW through domestication and diversification (long-timescale). Therefore, our results may lead to a change in RPW control strategies by switching to using safe alternative pesticide control methods (Resistant cultivars of date palm), which are underestimated and may reveal the impact of low-cost, but highly effective agricultural practices in the field of date production in the world. Understanding the genetic structure and calcium content of date palm cultivars mechanisms could help to predict date palm resistance against RPW populations in the new IPM strategy in RPW control.

The Effect of Date Palm Genotypes on Rhizobacterial Community Structures under Saline Environments.

Some genotypes of date palms (Phoenix dactylifera L.) are salt-tolerant; however, salinity significantly affects others. This study aimed to determine the root epiphytic bacterial contributions to the salt tolerance mechanism in the date palm and to verify if the salt-tolerant "Umsila" and the salt-susceptible "Zabad" cultivars have different bacterial communities. Therefore, the epiphytic bacterial community structures were investigated in both cultivars when grown under control and salinity conditions. The proximal soils of the roots were collected, the DNA was extracted, and a culture-independent approach using Illumina® MiSeq™ sequence analysis was carried out to identify the changes in the bacterial community structures in the soil samples due to the changes in salinity and the genotypes of the plants based on 16S rRNA gene sequencing. While salt tolerance response differences were evident between the two cultivars, the 16S rRNA gene sequencing results revealed 771 operational taxonomic units (OTUs), including 62 that were differentially accumulated in response to salinity. The ordination analysis showed significant (p = 0.001) changes among the communities in response to salinity in both cultivars. However, the results showed that the two cultivars had distinct bacterial communities when grown under controlled conditions, whereas they had a more similar bacterial community structure when grown under salinity conditions. The plant genotype does not affect the epiphyte bacterial community structure under salinity, probably because salinity affects the plant-microbe interaction similarly in both cultivars. Also, the identified rhizospheric bacteria are not directly associated with the root's physiological processes in response to salinity.

Genetic diversity of Libyan date palms cultivars using amplified fragment length polymorphism and biochemical analysis

Phoenix dactylifera L. is a flowering plant species commonly known as the date palm and is widely cultivated in most Middle East countries, including Libya. The present study analysed the biochemical and genetic diversity of fully mature eight Libyan date palm cultivars grown in different regions using the amplified fragments length polymorphism (AFLP) technique. Six pairs of AFLP molecular marker combinations were utilised to discriminate the eight date palm genotypes. Fruit dimensions (length x diameter) varied based on the type; Majhool Alheelo fruit had the highest value (15.29 cm2), while the lowest value was for Alkhadraya fruits (7.9 cm2). Reducing sugar content ranged from 10.4 per cent of flesh dry weight in Umfetity cultivars to 61.2 per cent in Sufeer-genab, which also showed the highest polymorphism percentage (P%=4.9), while Alkhadarya was the lowest (P%=0.519). The phylogenetic tree indicated that the most distantly related cultivars were Sufeer-genab, Alhamraya and Majhool Alhelo. The two most closely related cultivars were the Alsaeedy Show and Alkhadarya, grown in different regions. Our results indicate that the nutritional and genetic diversity of Libyan cultivars is not closely matched with the growing region.

Effect of flowering stage and storage conditions on pollen quality of six male date palm genotypes

Availability of efficient male genotypes is critical for successful artificial pollination and regular bearing of female date palms. The effect of flowering stage and storage conditions on pollen quality of six male date palm genotypes encoded ‘ABD1′, ‘P4′, ‘P3′, ‘P8′, ‘P7′ and ‘P13′were evaluated. Pollen collected from spathes developed at the middle of flowering stage exhibited the best viability (90%) and germinability (85%) compared to other stages. Pollen viability was greater than 90%, except for ‘P8′ that exhibited 80%, while, germinability greatly varied among the genotypes. Pollen quality decreased during 4 months of storage upon genotype and temperature, with a minimum reduction at −30 °C followed by 4 °C. Heat shock exposure (33 ± 2 °C) following storage revealed that pollen stored at −30 °C or 4 °C should be used for pollination on the same day of take out to avoid dramatic quality loss. The ‘ABD1′, an early flowering genotype, proved highest pollen quality both at fresh stage and after storage. While, the ‘P3′, a late flowering genotype, retained its pollen quality during storage. However, the ‘P13′ genotype exhibited excellent pollen quality when fresh, but greatly loses germinability during storage.

Genetic diversity and population structure of date palms (Phoenix dactylifera L.) in Ethiopia using microsatellite markers

BackgroundDate palm tree (Phoenix dactylifera L.) is a perennial monocotyledonous plant belonging to the Arecaceae family, a special plant with extraordinary nature that gives eminent contributions in agricultural sustainability and huge socio-economic value in many countries of the world including Ethiopia. Evaluation of genetic diversity across date palms at DNA level is very important for breeding and conservation. The result of this study could help to design for genetic improvement and develop germplasm introduction programmes of date palms mainly in Ethiopia. ResultsIn this study, 124 date palm genotypes were collected, and 10 polymorphic microsatellite markers were used. Among 10 microsatellites, MPdCIR085 and MPdCIR093 loci showed the highest value of observed and expected heterozygosity, maximum number of alleles, and highest polymorphic information content values. A total of 112 number of alleles were found, and the mean number of major allele frequency was 0.26, with numbers ranging from 0.155 (MPdCIR085) to 0.374 (MPdCIR016); effective number of alleles with a mean value of 6.61, private alleles ranged from 0.0 to 0.65; observed heterozygosity ranged from 0.355 to 0.726; expected heterozygosity varied from 0.669 to 0.906, polymorphic information content with a mean value of 0.809; fixation index individuals relative to subpopulations ranged from 0.028 for locus MPdCIR032 to 0.548 for locus MPdCIR025, while subpopulations relative to total population value ranged from − 0.007 (MPdCIR070) to 0.891 (MPdCIR015). All nine accesstions, neighbour-joining clustering analysis, based on dissimilarity coefficient values were grouped into five major categories; in population STRUCTURE analysis at highest K value, three groups were formed, whereas DAPC separated date palm genotypes into eight clusters using the first two linear discriminants. Principal coordinate analysis was explained, with a 17.33% total of variation in all populations. Generally, the result of this study revealed the presence of allele variations and high heterozygosity (> 0.7) in date palm genotypes. ConclusionsMicrosatellites (SSR) are one of the most preferable molecular markers for the study of genetic diversity and population structure of plants. In this study, we found the presence of genetic variations of date palm genotypes in Ethiopia; therefore, these genetic variations of date palms is important for crop improvement and conservation programmes; also, it will be used as sources of information to national and international genbanks.

Genetic diversity assessment in some landraces and varieties of date palm (Phoenix dactylifera L.) from Afar Region, Ethiopia, using ISSR markers

Despite its economic importance and nutritional value, few genetic resources are available for the enhancement of productivity of date palm ( Phoenix dactylifera L.) in Ethiopia. To date, there has been no genetic diversity study and proper characterization of Ethiopian landraces. In this study, the genetic variation among eight representative date palm genotypes cultivated in Afar region, Ethiopia was investigated using 15 inter-simple sequence repeat (ISSR) markers. Leaf samples were used for DNA extraction and PCR assay. Markers across 8 date palm genotypes were scored for their presence (1) or absence (0). Percentage polymorphism and gene diversity were analyzed using the binary matrix. To measure the informativeness of the ISSR primer polymorphic information content (PIC) and Shannon's information index (I) were also calculated. The distance matrix was generated and computed to cluster the data and draw precise relationships among the eight genotypes. Results indicated a high level of polymorphism (69.91%) in the genotypes. ISSR primers ID-438229, ID-438238, ID-438239 and ID-438243 scored the highest level of polymorphism (85.7–100%), PIC (0.3–0.37) and I (0.41–0.54) value, indicated that they can be effectively used in genetic studies of the date palm. The results revealed considerable diversity within date palm landraces. Cluster analysis and principal component analysis (PCoA) separated the two landraces, Harisa and Gewane, each other and from other groups, suggested that these genotypes can be considered as distinct genotypes in further evaluations of Ethiopian date palm. The findings of this study will lay the foundation for germplasm conservation, discovering superior genetic material and breeding fine varieties in date palm.

Conservation of superior Egyptian date palm genotypes through in vitro culture of inflorescence explants

Using floral buds could help to conserve the date palm biodiversity and finding a way to rapidly multiply the landraces with socioeconomic value. Siwa oasis in Egypt can be considered as biodiversity center of date palm. Several competitive date palms emerged from seeds, a variety at risk of distinction named Ghazal and top commercial variety 'Siwy' were selected based on fruit phenotype and evaluated. Upon flowering an immature spathe was technically excised from each parent tree and transferred to the laboratory for micropropagation. The in vitro plantlets of these endangered and superior genotypes were obtained within a single year. The steps carried out to achieve this target were described and discussed in the current study.

Comparative Metabolic Profiling of Two Contrasting Date Palm Genotypes Under Salinity

Since specific metabolites may be associated with salinity tolerance, this study aimed to decipher the salinity tolerance mechanism in date palm based on the information encoded by the metabolomic profiles of the salt-tolerant “Umsila” and salt-susceptible “Zabad” cultivars when grown under salinity conditions. Changes in the metabolomic profiles of the leaf and root tissues were determined using hydrophilic interaction liquid chromatography (HILIC) and reverse-phase liquid chromatography (RPLC) mass spectrometry. The global untargeted metabolomic analysis showed the presence of 4878 metabolites accumulated in leaf and root tissues of the date palm seedlings. Principal component analysis (PCA) revealed the presence of unique groups of metabolites for each treatment and tissue type. Pathway analysis showed the involvement of some of these metabolites in the biosynthesis of several types of membranous lipids and glycolipids molecules such as 18:0-lyso-phosphatidylethanolamine (lysoPE), and also the synthesis of cell-wall components such as 16-hydroxy hexadecanoic acid, which is an intermediate metabolite in cutin, suberin, and wax biosynthesis. Moreover, antioxidant flavonoids such as (+)-catechin and epicatechin, vitamins such as B9, phytohormone-associated compounds such as dihydrozeatin-9-N-glucoside-O-glucoside, and osmolytes such as the sulfonic amino acid taurine were all significantly (p ≤ 0.05, FWER ≤ 0.05) altered in response to salinity in both cultivars. These results indicate that salinity tolerance in date palm involved a multi-dimensional mechanism, which includes the modification of the cell-wall and cellular membranes, the production of oxygen species scavengers, the adjustment of cellular osmotic pressure, and probably the alteration of the hormonal balance. The intracultivar metabolomic profile comparison strategy performed in this study represents an approach that may pave the road toward the identification of salinity tolerance mechanisms in date palm based on the final protein products.

In vitro response of date palm (Phoenix dactylifera L.) inflorescence explants to high 2iP and 2,4-D concentrations

One of the major problems related to the implementation of date palm crops in Brazil is propagation. Therefore, the aim of this study was to evaluate the possibility of using tissue culture technique for the in vitro propagation of this species. Hence, the effect of 2iP and 2,4-D on the in vitro response of date palm inflorescence tissues, related to floral bud swelling, callusing, and rhizogenesis, was evaluated. The absence of 2,4-D was more detrimental to the in vitro response of inflorescence bud explants than absence of 2iP. In treatments without addition of 2,4-D to the culture medium, explants did not have swelling, callus or root formation. The treatment containing 150 mg/L 2,4-D in the presence of 1.5 mg/L 2iP initiated explant swelling, and treatments with either 100 mg/L or 150 mg/L 2,4-D, combined with 3.0 mg/L 2iP, were also efficient in stimulating in vitro swelling of inflorescence buds. Rhizogenesis was induced at the highest concentrations of 2,4-D (100 and 150 mg/L), combined with 4.5 mg/L 2iP, and was visually more evident in the treatment containing 150 mg/L 2,4-D + 4.5 mg/L 2iP. These results suggest that even higher concentrations of these two reagents might be efficient in the micropropagation of new existing date palm genotypes in the Submedium São Francisco River Valley.

Gene-Targeted markers to assess genetic diversity and population structure within Tunisian Phoenix dactylifera L. cultivars

Abstract Genetic variability in date palm genotypes collected from different regions of southern Tunisia was analyzed using a Start Codon Targeted (SCoT) marker system. Thirty-one accessions collected from three locations were investigated. One hundred and nine amplicons were produced among which 84 % were polymorphic. The PIC value and the Rp values testified of the efficiency of used primers. The percentage of polymorphic loci (Pp) varied from 44.57 to 83.70 %, Nei‘s gene diversity (H) from 0.175 to 0.273 with a mean of 0.228, and Shannon‘s information index (I) values ranging from 0.257 to 0.409 with an average value of 0.338 were illustrated. The Tunisian date palm populations exhibited high genetic differentiation (GST = 0.319) and gene flow (Nm = 1.063). The AMOVA analysis presented 70 % of the variation within the population and 30 % of the variation between them. Phylogenetic analysis and the Bayesian clustering approach also revealed high genetic variation among genetic variants with a net divergence of the wild insular population of Kerkennah from other cultivars. The present investigation suggests the effectiveness of the SCoT marker system to estimate the genetic diversity of Phoenix dactylifera genotypes.

Comparative Water Relations of Two Contrasting Date Palm Genotypes under Salinity

Salinity is a global agricultural problem, resulting in a significant reduction in the plantation areas and the crop yields, especially in arid and semiarid regions. The date palm is relatively salt-tolerant plant species, although the nature of salt tolerance is poorly understood. In this study, the salt stress responses of a salt-tolerant “Umsila” was compared with salt-susceptible “Zabad” date palm cultivars. Various physiological parameters, plant-water relations, and anatomical characteristics were analyzed. The results revealed that although salinity has negatively affected both cultivars, Umsila exhibited more stable photosynthesis than Zabad as reflected by the quantum yield (Qy) and the stomatal conductance (GS). Similarly, Umsila showed a more dynamic root system and efficient water relations than Zabad as demonstrated by the leaf water potential (LWP) and relative water content (RWC) during salinity. Umsila also accumulated greater abundances of soluble sugars, potassium (K+), calcium (Ca+2), proline, glycine betaine, and lignin and formed extra layers of Casparian strips in the root tissues when the seedlings were grown under saline conditions. Together, the results obtained from this study have offered some insights into the salt tolerance mechanisms in the date palm.

Genetic Diversity of Egyptian Date Palms (Phoenix dactylifera L.) Using Morphological and Molecular Markers

Morphological and molecular analyses were conducted to evaluate the genetic diversity among eleven Egyptian date palms (Phoenix dactylifera L.). Ten SSR primer pairs revealed a high percentage of polymorphism (97.4%) among 38 total number of alleles, while 11 SCoT primers produced 48.5% from 171 amplified fragments. SCoTs recorded effective multiplex ratio (EMR) and PIC values of 7.5 and 0.14, respectively, opposing to 3.7 and 0.26 for SSRs, respectively. A similar marker index has thus resulted in both markers. Nei’s gene diversity (h) was generally low for both marker systems indicating homogeneous nature and narrow genetic background for the studied Egyptian date palms, which was also emphasized through their high genetic similarity estimates. The results of UPGMA cluster analysis and PCoA grouped the eleven date palms according to their geographical location and sex. In addition to classical morphological characters, the current study confirmed the importance of using SCoTs as functionally gene-based multi-loci markers besides nuclear SSR loci to assess the genetic variations and cultivar identification among Egyptian date palm genotypes

Genetic diversity of Tunisian male date palm (Phoenix dactylifera L.) genotypes using morphological descriptors and molecular markers

Twenty-eight morphological characters (consisting of 15 quantitative and 13 qualitative traits) and eight SSR loci were used to study morphological and genetic diversity of 24 male date palm genotypes from Southern Tunisia. The results revealed that fourteen of the fifteen quantitative characters studied showed a high discriminating power to distinguish male date palm trees. UPGMA clustering based on morphological data classified the samples studied in five clusters. The eight SSR loci used showed polymorphism resulting in a total of 42 alleles in the samples analyzed. The number of alleles per locus varied from 3 (mPdCIR35 and mPdCIR63) to 7 (mPdCIR 25 and mPdCIR 32) with a mean of 5.4 alleles per locus. The average of observed heterozygosity (Ho), ranged between 0.13 (mPdCIR78) and 0.79 (mPdCIR25), with a mean of 0.54. The average of expected heterozygosity (He) ranged between 0.32 (mPdCIR78) and 0.74 (mPdCIR57 and mPdCIR63) with a mean of 0.61. Fis values were negative for all the markers excepted for mPdCIR015, mPdCIR035 and mPdCIR078. Fst values varied between 0.04 (mPdCIR015 and mPdCIR063) to 0.29 (mPdCIR063). The dendrogram constructed based on the data from the eight SSR primers revealed 3 clusters. No correlation (r= -0,106, p = 0.075) was obtained between distances based on quantitative morphological traits and genetic distances using the Mantel test. Results indicate a high degree of genetic diversity among date palm pollinizers in southern Tunisia, but the accessions do not group according to geographical origin due probably to the exchange of plant material and seeds among different regions of the country.

Validation of RAPD and ISSR Markers Used for Sex Determination in Date Palm Grown under Sudan Conditions

Abstract Date palm is one of the most important economical crops in the world. Sex determination of date palm in early stage is a prerequisite for breeding and cultivation. The aim of this study is to validate RAPD and ISSR markers for sex identification of date palm genotypes grown under Sudan conditions. DNA was extracted from ten seedlings and five male and female plants using CTAB method. Eight primers, six RAPD and two ISSR primers were examined for their validation in sex determination of date palm genotypes. PCR amplification was performed using these primers. Four RAPD primers OPA02, OPJ-09, RD A02 and RD A21 were amplified male specific band with size of 1000, 1100, 1000 and 1400 pb respectively, while ISSR markers could not. The specific bands were observed clearly among all male genotypes and absent in female samples unknown samples irrespective of genotypes. Our results could be useful for sex determination of date palm sex in seedling stage and would promote date palm cultivation and production.

Spatial distribution and genetic diversity of wild date palm (Phoenix sylvestris) growing in coastal Bangladesh

The aim of this study was to explore the prospects of integrating simple sequence repeat (SSR) or microsatellite marker data into a geographical information system to anticipate spatial distribution of allelic diversity of wild date palms in Bangladesh. The genetic diversity, spatial distribution, and population structure were assessed in 38 genotypes of wild date palms using 12 SSR primer pairs. A total of 67 alleles were counted ranging from 4 (KSU-PDL74) to 8 (MPdCIR070). Major allele frequency was in the range of 0.26 (MPdCIR032) to 0.89 (KSU-PDL74), polymorphic information content ranged from 0.18 (KSU-PDL74) to 0.75 (MPdCIR032), and gene diversity ranged from 0.19 (KSU-PDL74) to 0.77 (MPdCIR032). Three major clusters were formed by the unrooted tree grouping. The population structure divided 38 genotypes into six populations. Population 1 and Population 2 each contained seven pure genotypes while Populations 3, 4, 5, and 6 contained 6, 4, 3, and 3 pure genotypes, respectively. The remaining eight genotypes were admixtures. The pairwise Fst estimate among sub-groups indicated that the six populations are undoubtedly different from each other. The date palm genotypes of Amtoli, Doshmina, and Kuakata in coastal Bangladesh contained the highest allelic diversity (13–15). SSR2-80 and SSR5-80 were considered to be the most important alleles for the identification of areas with unique diversity as these alleles are repetitively found in a small geographic area. Locally common alleles of Bangladeshi wild date palm were identified. Outcomes of this research will offer valuable guidelines for future breeding strategies and will be beneficial for assessment and conservation of Bangladeshi wild date palm genetic resources.

Development of Sex-Specific PCR-Based Markers in Date Palm.

Molecular markers are used efficiently in the development and identification of gender-specific PCR-based markers in date palm. There is mounting evidence that different marker systems vary in their mechanisms of detecting polymorphism and genome coverage. Therefore, they could complement each other to generate accurate sex-specific markers in date palm. This chapter describes the uses of PCR-based molecular markers to develop and identify the gender in different date palm genotypes; these are amplified fragment length polymorphism (AFLP), start codon targeted polymorphism (SCoT), conserved DNA-derived polymorphism (CDDP), intron-targeted amplified polymorphism (ITAP), and random amplified polymorphic DNA (RAPD). Also described is how to characterize the identified markers by Sanger sequencing and to explore their functions through alignment of their sequences with the Genbank databases.